Air monitoring issues when commissioning a new facility
One of the most critical steps facility managers can take when seeking to understand air-monitoring in a new facility is committing to a rigorous commissioning process.
One of the most critical steps facility managers can take when seeking to understand air-monitoring in a new facility is committing to a rigorous commissioning process. Proper commissioning can help determine appropriate requirements for air monitoring during the design review phase. Later in the commissioning process, comprehensive functional performance testing of building systems prior to occupancy confirms design and construction components that impact indoor air quality are properly installed and operating.
Using commissioning to help plan ongoing air monitoring helps maintain strong conditions—the National Institute for Occupational Safety and Health (NIOSH) has found 52% of the primary sources of indoor air quality problems are related to inadequate ventilation. Delivering a healthy environment, serviceable systems, and energy efficient operation are the overriding goals of the commissioning process and air monitoring is an important tool to achieve these goals.
Commissioning focuses on two key aspects of air-monitoring: the air quantity and the air quality.
One of the prerequisites in commissioning before final functional testing can begin is to have a complete air balancing performed on all HVAC and air-delivery systems. Air balancing does the following.
-- It confirms adequate air is provided in all areas of a facility to achieve the design intent.
-- It helps uncover and resolve issues before occupancy, such as airflow restrictions or leakage.
-- It improves energy efficiency and functionality by uncovering unintended air distribution.
After initial duct pressure testing and air balancing is complete, it is important to continue monitoring the airflow to verify initial performances you are maintained. This is imperative in critical areas where pressure relationships between zones must be maintained like laboratories, isolation rooms, and vivarium spaces. During the commissioning process, the commissioning authority verifies those pressure relationships are maintained regardless of the HVAC system’s operating mode, to provide a safe and healthy environment. The level of complexity can increase if different areas have different heating and cooling requirements, heat generation by specialized apparatuses, exhaust requirements, and pressurization needs. A holistic and complete approach studying the interrelationships between all of these different components is critical for a complete commissioning process.
After the design team determines the required air quality and conducts a thorough review of reference standards, the design phase commissioning review will confirm this level is achieved in an efficient manner. A calculated fixed-air replacement rate might prove energy wasteful and does not guarantee appropriate levels of fresh air. Air monitoring can control the rate of fresh air intake of a building dynamically based on actual need.
Air monitoring becomes even more paramount when considering spaces that may see a varying level of occupancy and use. While a design may provide the necessary level of ventilation at a worst case allowable use, this use may never or rarely occur. Air monitoring, and a commissioned integration with the building automation system, allows the building systems to cycle down when spaces are not used at the maximum design capacity.
Air monitoring can also help control pollutant levels in the building derived from an outdoor source. For example, detection of a pollutant such as carbon monoxide from idling vehicles from an adjacent parking garage can engage an HVAC control sequence that would mitigate this situation and/or send an alarm to appropriate personnel that can resolve the condition. Proper system reaction and alarm functionality are verified during the commissioning process.
With the additional complexity and integration of different systems (e.g. lighting, HVAC, hood operation, load shedding), buildings are becoming more “intelligent” as long as building systems are working as intended and communicating with one another as necessary. Air monitoring is a system that allows a laboratory to function in an efficient and reliable manner while achieving air quality requirements for the stated purpose. Confirming design intent during turnover and operation is the reason commissioning is essential for animal laboratories so that they achieve the high level of performance that is required.